The Search for the Ideal Chapter Length
As a group, new writers are worriers. They're always troubled that they're doing something, everything wrong, and end up going in search of some set of rules to tell them what to do. Very often, they find their way to people who are long on confidence but short on hard facts.
A major topic of concern is the metric of length. Overall book length, of course - that's important because agents take that into account. Understanding short story and article length is vital to anyone submitting pieces to markets. Even sentence and paragraph length have been discussed in depth in various venues.
But lately, I've noticed a lot of people worrying over chapter length - and sure enough, a lot of very opinionated people speaking with great authority on the topic. There are a lot of people out there who know for a fact that a certain chapter is too long or (less commonly) too short.
So where does this come from?
A Quick Exercise
Before we get to my analysis, I'd like you to do something. Think of a novel you've read, one that you're familiar with. Really go easy on yourself - pick one that you've read multiple times, or the one you've read most recently.
Ready? Okay, here we go:
What is the average length - in pages - of the chapters in that book?
Not sure? I'll make it even easier - let's go over/under. Is the average chapter longer or shorter than 8 pages? Longer or shorter than 12 pages?
Go ahead and go check, if you're in a position to do so. I'll wait.
Real World Chapter Lengths
I'm guessing that you found this somewhat difficult, which was the point of this exercise. Chapters are a structural element that are not strictly necessary, but serve various functions. They may be used to mark new "scenes," split up POVs, indicate a change in time or place, or introduce cliffhangers. Alternately, they may just be there for readability or navigation purposes - in which case they are, technically, superfluous and could be removed without affecting the narrative.
My gut instinct is that, despite all the finger-wagging, that there really isn't a typical chapter length (the fact that no one agrees on how long a chapter "should" be suggests this). However, I'm not one to just leave this to the gut, so I did a little bit of information gathering. I decided to take an essentially random assortment of popular novels and glean the length of just the first chapter in each.
Here are my standards: All of the novels I used were originally written in English and have a relatively standard format. Beyond that, they are an odd bunch - classic and modern, literary and commercial, general market and young adult, and a scattering of genres. Here are the ones I used, in alphabetical order:
The Da Vinci Code
The Fault in Our Stars
The Fellowship of the Ring
Harry Potter and the Sorcerer's Stone
The Hitchhiker's Guide to the Galaxy
The Hunger Games
The Hunt for Red October
Murder on the Orient Express
Ready Player One
Sense and Sensibility
To Kill a Mockingbird
As you can see, a varied lot - not much in common except that people seem to like them. I used the paperback version for each and tried to exclude prologues and other front-matter, counting the proper "Chapter 1" for each.
How close is it to what you assumed?
There are caveats here, of course. It is a small sample, not representative of the publishing industry as a whole. The differences in formatting make it hard to estimate word count, which is why I provided a range instead of a single estimate. The first chapter might not be representative of the book's chapters as a whole, and sometimes that chapter length may vary wildly. I'm certainly familiar with The Hitchhiker's Guide to the Galaxy, and I can tell you that some chapters are fourth-wall breaking asides that are as little as one page - far shorter than the first.
That last caveat kind of proves my point, though. If authors are willing to use chapters of varying lengths - for narrative purposes or simply as a matter of course - it suggests that there is no standard. And even if you were to sample thousands of books and average out the chapter lengths, the result might not be representative.
In other words, there is no length that a chapter "should" be.
Always Take Caution
There is no codex of rules that defines literature, no hard set of rules that must be followed. Consequently, you need to take anyone's advice as their opinion. Some of those opinions might carry more weight - if they're backed by industry experience or mathematical analysis - but they're opinions all the same. Even Vonnegut admitted at the end of his famous list that there are exceptions to all of his rules.
Anyone professing some kind of writing authority is trying to pull a fast one. At best, this is a person who doesn't know what she's talking about and is trying to look smart and show off. At worst, she's about to sell you something. Always use caution when taking advice - even mine.